Elisa Giorgio - Academia.edu (original) (raw)

Papers by Elisa Giorgio

Adult-onset autosomal dominant leukodystrophy (ADLD) is a slowly progressive neurological disorde... more Adult-onset autosomal dominant leukodystrophy (ADLD) is a slowly progressive neurological disorder characterized by autonomic dysfunction, followed by cerebellar and pyramidal features. ADLD is caused by duplication of the lamin B1 gene (LMNB1), which leads to its increased expression. The molecular pathways involved in the disease are still poorly understood. Hence, we analyzed global gene expression in fibroblasts and whole blood of LMNB1 duplication carriers and used Gene Set Enrichment Analysis to explore their gene signatures. We found that LMNB1 duplication is associated with dysregulation of genes involved in the immune system, neuronal and skeletal development. Genes with an altered transcriptional profile clustered in specific genomic regions. Among the dysregulated genes, we further studied the role of RAVER2, whichwe found to be overexpressed atmRNAand protein level. RAVER2 encodes a putative trans regulator of the splicing repressor polypyrimidine tract binding protein (...

Genes

The RAF1:p.Ser257Leu variant is associated with severe Noonan syndrome (NS), progressive hypertro... more The RAF1:p.Ser257Leu variant is associated with severe Noonan syndrome (NS), progressive hypertrophic cardiomyopathy (HCM), and pulmonary hypertension. Trametinib, a MEK-inhibitor approved for treatment of RAS/MAPK-mutated cancers, is an emerging treatment option for HCM in NS. We report a patient with NS and HCM, treated with Trametinib and documented by global RNA sequencing before and during treatment to define transcriptional effects of MEK-inhibition. A preterm infant with HCM carrying the RAF1:p.Ser257Leu variant, rapidly developed severe congestive heart failure (CHF) unresponsive to standard treatments. Trametinib was introduced (0.022 mg/kg/day) with prompt clinical improvement and subsequent amelioration of HCM at ultrasound. The appearance of pulmonary artery aneurysm and pulmonary hypertension contributed to a rapid worsening after ventriculoperitoneal shunt device placement for posthemorrhagic hydrocephalus: she deceased for untreatable CHF at 3 months of age. Autopsy s...

American Journal of Medical Genetics Part A

De novo variants in the WDR26 gene leading to haploinsufficiency have recently been associated wi... more De novo variants in the WDR26 gene leading to haploinsufficiency have recently been associated with Skraban‐Deardorff syndrome. This condition is an ultra‐rare autosomal dominant neurodevelopmental disorder characterized by a broad range of clinical signs, including intellectual disability (ID), developmental delay (DD), seizures, abnormal facial features, feeding difficulties, and minor skeletal anomalies. Currently, 18 cases have been reported in the literature and for only 15 of them a clinical description is available. Here, we describe a child with Skraban‐Deardorff syndrome associated with the WDR26 pathogenic de novo variant NM_025160.6:c.69dupC, p.(Gly24ArgfsTer48), and an adult associated with the pathogenic de novo variant c.1076G > A, p.(Trp359Ter). The adult patient was a 29‐year‐old female with detailed information on clinical history and pharmacological treatments since birth, providing an opportunity to map disease progression and patient management. By comparing our cases with published reports of Skraban‐Deardorff syndrome, we provide a genetic and clinical summary of this ultrarare condition, describe the clinical management from childhood to adult age, and further expand on the clinical phenotype.

The primary anatomical defect leading to periventricular nodular heterotopia occurs within the ne... more The primary anatomical defect leading to periventricular nodular heterotopia occurs within the neural progenitors along the neuroepithelial lining of the lateral ventricles and results from a defect in the initiation of neuronal migration, following disruption of the neuroependyma and impaired neuronal motility. Growing evidence indicates that the FLNA-dependent actin dynamics and regulation of vesicle formation and trafficking by activation of ADP-ribosylation factors (ARFs) can play an important role in this cortical malformation. We report the first inherited variant of ARF1 in a girl with intellectual disability and periventricular nodular heterotopia who inherited the variant from the father with previously undiagnosed single nodular heterotopia and mild clinical expression. Additionally, both patients presented some features suggestive of hypohidrotic ectodermal dysplasia. These clinical features showed similarities to those of three previously reported cases with ARF1 missens...

Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal-dominant neurodegenerative ... more Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal-dominant neurodegenerative disorders involving the cerebellum and 23 different genes. We mapped SCA38 to a 56 Mb region on chromosome 6p in a SCA-affected Italian family by whole-genome linkage analysis. Targeted resequencing identified a single missense mutation (c.689G>T [p.Gly230Val]) in ELOVL5. Mutation screening of 456 independent SCA-affected individuals identified the same mutation in two further unrelated Italian families. Haplotyping showed that at least two of the three families shared a common ancestor. One further missense variant (c.214C>G [p.Leu72Val]) was found in a French family. Both missense changes affect conserved amino acids, are predicted to be damaging by multiple bioinformatics tools, and were not identified in ethnically matched controls or within variant databases. ELOVL5 encodes an elongase involved in the synthesis of polyunsaturated fatty acids of the u3 and u6 series. Arachidoni...

Frontiers in Molecular Biosciences

Missense variants are among the most studied genome modifications as disease biomarkers. It has b... more Missense variants are among the most studied genome modifications as disease biomarkers. It has been shown that the “perturbation” of the protein stability upon a missense variant (in terms of absolute ΔΔG value, i.e., |ΔΔG|) has a significant, but not predictive, correlation with the pathogenicity of that variant. However, here we show that this correlation becomes significantly amplified in haploinsufficient genes. Moreover, the enrichment of pathogenic variants increases at the increasing protein stability perturbation value. These findings suggest that protein stability perturbation might be considered as a potential cofactor in diseases associated with haploinsufficient genes reporting missense variants.

Pediatric Blood & Cancer

To the Editor: Osteopathia striata with cranial sclerosis (OSCS,MIM#300373) is a rare X-linked do... more To the Editor: Osteopathia striata with cranial sclerosis (OSCS,MIM#300373) is a rare X-linked dominant skeletal dysplasia characterised by linear striations in the metaphyseal region of the long bones and pelvis in combination with cranial sclerosis owing to increased osteoblast activity.1,2 The rarity and heterogeneity of its phenotype makes a diagnosis of OSCS challenging, leading to the risk that it can actually be missed for many years. Jenkins et al. found that OSCS is caused by germline deletions/mutations of the AMER1 gene (MIM#300647, NM_152424.4) located on Xq11.2.3 Somatic mutations in AMER1 are found in 7–29% ofWilms tumours (WT).4–7 To date, and to the best of our knowledge, just five cases of paediatric tumours, fourWTandonehepatoblastoma, havebeen reported in patientswithOSCS8–10 despite two large studies investigating cohorts of patients (including adults) with OSCS did not find an increased risk of cancer.3,11 Herein, we report a clinical and molecular description of an additional girl affected byOSCSwho developed aWT. The girl was born at 35 weeks of gestation to healthy nonconsanguineous parents. At her birth, macrocephaly, a prominent forehead, retrognathia, anteverted nares, hypertelorism and pectus excavatum were all observed. The neonatal audiometry was normal. The brain magnetic resonance imaging was unremarkable except for the evidence of macrocephaly. During follow-up, a mild intellectual disability (ID) became evident in the girl, particularly in speech ability. Later, at the age of 4, the patient began to experience a painless rapid increase in abdominal volume. A computed tomography (CT) scan showedacapsulatedpolycyclic hypo-vascularised retroperitoneal mass with necrotic areas, compatible with a renal tumour. A chest CT was also performed and resulted negative for metastases, but intriguingly, the chest X-ray inadvertently revealed longitudinal sclerotic striations in the humeral metaphysis (Figure 1). Similarly, the radiographs of her long bones demonstrated prominent linear sclerotic striations in the metaphyses and epiphyses and fan-like striations of the iliac crest (Figure 1). The girl underwent a core needle biopsy of the lesion, which confirmed our suspicion ofWT. After this diagnosis, the girl started neoadjuvant chemotherapy according to the contemporary national protocol. At nephrectomy, pathology inspection revealed a mixed epithelial and blastemal WT, with no associated nephrogenic rests, stage

International Journal of Molecular Sciences

Diseases associated with acquired or genetic defects in members of the chaperoning system (CS) ar... more Diseases associated with acquired or genetic defects in members of the chaperoning system (CS) are increasingly found and have been collectively termed chaperonopathies. Illustrative instances of genetic chaperonopathies involve the genes for chaperonins of Groups I (e.g., Heat shock protein 60, Hsp60) and II (e.g., Chaperonin Containing T-Complex polypeptide 1, CCT). Examples of the former are hypomyelinating leukodystrophy 4 (HLD4 or MitCHAP60) and hereditary spastic paraplegia (SPG13). A distal sensory mutilating neuropathy has been linked to a mutation [p.(His147Arg)] in subunit 5 of the CCT5 gene. Here, we describe a new possibly pathogenic variant [p.(Leu224Val)] of the same subunit but with a different phenotype. This yet undescribed disease affects a girl with early onset demyelinating neuropathy and a severe motor disability. By whole exome sequencing (WES), we identified a homozygous CCT5 c.670C>G p.(Leu224Val) variant in the CCT5 gene. In silico 3D-structure analysis a...

Journal of Medical Genetics

IntroductionThe Tousled-like kinases 1 and 2 (TLK1 and TLK2) are involved in many fundamental pro... more IntroductionThe Tousled-like kinases 1 and 2 (TLK1 and TLK2) are involved in many fundamental processes, including DNA replication, cell cycle checkpoint recovery and chromatin remodelling. Mutations in TLK2 were recently associated with ‘Mental Retardation Autosomal Dominant 57’ (MRD57, MIM# 618050), a neurodevelopmental disorder characterised by a highly variable phenotype, including mild-to-moderate intellectual disability, behavioural abnormalities, facial dysmorphisms, microcephaly, epilepsy and skeletal anomalies.MethodsWe re-evaluate whole exome sequencing and array-CGH data from a large cohort of patients affected by neurodevelopmental disorders. Using spatial proteomics (BioID) and single-cell gel electrophoresis, we investigated the proximity interaction landscape of TLK2 and analysed the effects of p.(Asp551Gly) and a previously reported missense variant (c.1850C>T; p.(Ser617Leu)) on TLK2 interactions, localisation and activity.ResultsWe identified three new unrelated ...

Frontiers in Cell and Developmental Biology

Previous studies in developing Xenopus and zebrafish reported that the phosphate transporter slc2... more Previous studies in developing Xenopus and zebrafish reported that the phosphate transporter slc20a1a is expressed in pronephric kidneys. The recent identification of SLC20A1 as a monoallelic candidate gene for cloacal exstrophy further suggests its involvement in the urinary tract and urorectal development. However, little is known of the functional role of SLC20A1 in urinary tract development. Here, we investigated this using morpholino oligonucleotide knockdown of the zebrafish ortholog slc20a1a. This caused kidney cysts and malformations of the cloaca. Moreover, in morphants we demonstrated dysfunctional voiding and hindgut opening defects mimicking imperforate anus in human cloacal exstrophy. Furthermore, we performed immunohistochemistry of an unaffected 6-week-old human embryo and detected SLC20A1 in the urinary tract and the abdominal midline, structures implicated in the pathogenesis of cloacal exstrophy. Additionally, we resequenced SLC20A1 in 690 individuals with bladder exstrophy-epispadias complex (BEEC) including 84 individuals with cloacal exstrophy. We identified two additional monoallelic de novo variants. One was identified in a case-parent trio with classic bladder exstrophy, and one additional novel de novo variant was detected in an affected mother who transmitted this variant to her affected son. To study the potential cellular impact of SLC20A1 variants, we expressed them in HEK293 cells. Here, phosphate transport was not compromised, suggesting that it is not a disease mechanism. However, there was a tendency for lower levels of cleaved caspase-3, perhaps implicating apoptosis pathways in the disease. Our results suggest SLC20A1 is involved in urinary tract and urorectal development and implicate SLC20A1 as a disease-gene for BEEC.

Human Mutation

In genetic diseases, the most prevalent mechanism of pathogenicity is an altered expression of do... more In genetic diseases, the most prevalent mechanism of pathogenicity is an altered expression of dosage‐sensitive genes. Drugs that restore physiological levels of these genes should be effective in treating the associated conditions. We developed a screening strategy, based on a bicistronic dual‐reporter vector, for identifying compounds that modulate protein levels, and used it in a pharmacological screening approach. To provide a proof‐of‐principle, we chose autosomal dominant leukodystrophy (ADLD), an ultra‐rare adult‐onset neurodegenerative disorder caused by lamin B1 (LMNB1) overexpression. We used a stable Chinese hamster ovary (CHO) cell line that simultaneously expresses an AcGFP reporter fused to LMNB1 and a Ds‐Red normalizer. Using high‐content imaging analysis, we screened a library of 717 biologically active compounds and approved drugs, and identified alvespimycin, an HSP90 inhibitor, as a positive hit. We confirmed that alvespimycin can reduce LMNB1 levels by 30%–80% in five different cell lines (fibroblasts, NIH3T3, CHO, COS‐7, and rat primary glial cells). In ADLD fibroblasts, alvespimycin reduced cytoplasmic LMNB1 by about 50%. We propose this approach for effectively identifying potential drugs for treating genetic diseases associated with deletions/duplications and paving the way toward Phase II clinical trials.

Human Genetics

Autozygosity-driven exome analysis has been shown effective for identification of genes underlyin... more Autozygosity-driven exome analysis has been shown effective for identification of genes underlying recessive diseases especially in countries of the so-called Greater Middle East (GME), where high consanguinity unravels the phenotypic effects of recessive alleles and large family sizes facilitate homozygosity mapping. In Italy, as in most European countries, consanguinity is estimated low. Nonetheless, consanguineous Italian families are not uncommon in publications of genetic findings and are often key to new associations of genes with rare diseases. We collected 52 patients from 47 consanguineous families with suspected recessive diseases, 29 originated in GME countries and 18 of Italian descent. We performed autozygosity-driven exome analysis by detecting long runs of homozygosity (ROHs > 1.5 Mb) and by prioritizing candidate clinical variants within. We identified a pathogenic synonymous variant that had been previously missed in NARS2 and we increased an initial high diagnostic rate (47%) to 55% by matchmaking our candidate genes and including in the analysis shorter ROHs that may also happen to be autozygous. GME and Italian families contributed to diagnostic yield comparably. We found no significant difference either in the extension of the autozygous genome, or in the distribution of candidate clinical variants between GME and Italian families, while we showed that the average autozygous genome was larger and the mean number of candidate clinical variants was significantly higher ( p = 0.003) in mutation-positive than in mutation-negative individuals, suggesting that these features influence the likelihood that the disease is autozygosity-related. We highlight the utility of autozygosity-driven genomic analysis also in countries and/or communities, where consanguinity is not widespread cultural tradition.

British Journal of Haematology

Diamond–Blackfan anaemia (DBA) is a rare and heterogeneous disease characterised by hypoplastic a... more Diamond–Blackfan anaemia (DBA) is a rare and heterogeneous disease characterised by hypoplastic anaemia, congenital anomalies and a predisposition for malignancies. The aim of this paper is to report the findings from the Italian DBA Registry, and to discuss the Registry’s future challenges in tackling this disease. Our 20‐year long work allowed the connection of 50 Italian Association of Paediatric Haematology and Oncology (AIEOP) centres and the recruitment of 283 cases. Almost all patients have been characterised at a molecular level (96%, 271/283), finding a causative mutation in 68% (184/271). We confirm the importance of determination of erythrocyte adenosine deaminase activity (eADA) and of ribosomal RNA assay in the diagnostic pipeline and characterisation of a remission state. Patients with mutations in large ribosomal subunit protein (RPL) genes had a significant correlation with the incidence of malformations, higher eADA levels and more severe outcomes, compared to patients with mutations in small ribosomal subunit protein (RPS) genes. Furthermore, as a consequence of our findings, particularly the incidence of malignancies and the high percentage of patients aged >18 years, we stress the importance of collaboration with adult clinicians to guarantee regular multi‐specialist follow‐up. In conclusion, this study highlights the importance of national registries to increase our understanding and improve management of this complex disease.

Spinocerebellar ataxia 28 is an autosomal dominant neurodegenerative disorder caused by missense ... more Spinocerebellar ataxia 28 is an autosomal dominant neurodegenerative disorder caused by missense mutations affecting the proteolytic domain of AFG3L2, a major component of the mitochondrial m-AAA protease. However, little is known of the underlying pathogenetic mechanisms or how to treat patients with SCA28. Currently available Afg3l2 mutant mice harbour deletions that lead to severe, early-onset neurological phenotypes that do not faithfully reproduce the late-onset and slowly progressing SCA28 phenotype. Here we describe production and detailed analysis of a new knock-in murine model harbouring an Afg3l2 allele carrying the p.Met665Arg patient-derived mutation. Heterozygous mutant mice developed normally but signs of ataxia were detectable by beam test at 18 months. Cerebellar pathology was negative; electrophysiological analysis showed increased spontaneous firing in Purkinje cells from heterozygous mutants with respect to wild-type controls, although not statistically significan...

Journal of Human Genetics

Primary familial brain calcification (PFBC) is a rare disease characterized by brain calcificatio... more Primary familial brain calcification (PFBC) is a rare disease characterized by brain calcifications that mainly affect the basal ganglia, thalamus, and cerebellum. Among the four autosomal-dominant genes known to be associated with the disease, SLC20A2 pathogenic variants are the most common, accounting for up to 40% of PFBC dominant cases; variants include both point mutations, small insertions/deletions and intragenic deletions. Over the last 7 years, we have collected a group of 50 clinically diagnosed PFBC patients, who were screened for single nucleotide changes and small insertions/deletions in SLC20A2 by Sanger sequencing. We found seven pathogenic/likely pathogenic variants: four were previously described by our group, and three are reported here (c.303delG, c.21delG, and c.1795-1G>A). We developed and validated a synthetic Multiplex Ligation-dependent Probe Amplification (MLPA) assay for SLC20A2 deletions, covering all ten coding exons and the 5′ UTR (SLC20A2-MLPA). Using this method, we screened a group of 43 PFBC-patients negative for point mutations and small insertions/deletions, and identified two novel intragenic deletions encompassing exon 6 NC_000008.10:g.(42297172_42302163)_(423022281_42317413)del, and exons 7–11 including the 3′UTR NC_000008.10:g.(?_42275320)_(42297172_42302163)del. Overall, SLC20A2 deletions may be highly underestimated PFBC cases, and we suggest MLPA should be included in the routine molecular test for PFBC diagnosis.